The present invention relates generally to infusion pumps for administering intravenous fluids and more particularly to specific features of a peristaltic infusion pump.
At the outset, reference is made to co-pending United States Patent application Ser. No. 868,525 entitled PERISTALTIC INFUSION PUMP AND DISPOSABLE CASSETTE FOR USE THEREWITH, filed on Jan. 11, 1978 now U.S. Pat. No. 4,187,057 and assigned to the assignee of the present application. This co-pending application discloses a specific type of peristaltic infusion pump comprising a disposable cassette and pump arrangement. The cassette includes a continuous tubular arrangement adapted to pass intravenous liquids therethrough and a cassette body for fixedly supporting a predetermined tubular section of the tubular arrangement in an exposed and readily accessible position. The pump arrangement includes structure for supporting the disposable cassette for movement between a first inoperative position and a second, spaced apart operative position and a pump head cooperating with the exposed and readily accessible section of the tubular arrangement when the cassette is in its operative position for peristaltically pumping fluid through the tubular arrangement.
In addition to the features just recited, the peristaltic pump described in this co-pending application includes a conventinal electrically energized motor for driving the pump head and it may include conventional means for sensing occlusion in the tubular arrangement during operation of the pump and conventional means sensing the index of refraction of the intravenous fluid as it passes through the tubular arrangement for detecting the presence of air bubbles or the like. As will be seen hereinafter, the present invention is directed to a peristaltic infusion pump utilizing a particular drive motor including an unconventional way to energize this motor, and unconventional approaches to detecting the presence of occlusions within the tubular arrangement and changes in the index of refraction of the intravenous fluid passing through this arrangement.